In medical image viewing and computer aided diagnosis (CAD) applications, the user is regularly offered the opportunity to select a lesion or a tumor in a 3D medical image data set for imaging or processing. This selection may be performed by indicating a volume of interest which contains the lesion or tumor.
Known methods for such region-of-interest selection may allow the user to select a two-dimensional region of interest (2D ROI) in a user-selected 2D image slice. This 2D ROI may be automatically extended to a three-dimensional region of interest (3D ROI), or volume of interest (VOI). Alternatively, the user may be allowed to navigate through a stack of image slices and interactively place a 3D ROI, for example by drawing a contour in each image slice, or by indicating the first and last slice of the region of interest and a box or circle marking the boundaries of the ROI within the slices.
US 2009/0034684 discloses a method and system for displaying tomosynthesis images. The method includes displaying a bidimensional slice or slab image, selection on the displayed image of at least one volume of interest associated with a bidimensional region of interest located in the plane of the image, and displaying in the region of interest, according to the practitioner's wishes: images of slices of the volume of interest, three dimensional images of the volume of interest, and slabs obtained from the volume of interest. To define a volume of interest, one defines, on the displayed image, the position and size of a bidimensional region of interest, the position of the volume of interest being defined by the position of the region of interest and the depth of the volume of interest being adjusted automatically or manually. In the case where the displayed image is a slab, one defines the depth of the volume of interest as equal to the thickness of the slab.
The existing methods are perceived as not easy to use. Moreover it is not easy to visually inspect the three-dimensional region of interest.